Many arrangements are known for accommodating and connecting to inserted electronic devices, and some of these are adaptable to devices of varying sizes. Some have contacts which are exposed and simply make abutting contact as the device is inserted, but this type is very susceptible to accidental damage. Some arrangements have contacts mounted in a sliding sleeve which is engaged by the unit during insertion. Then, as the sleeve is driven inward by further insertion, cam surfaces and cam followers push the contacts toward the mating elements. Such devices can be completely satisfactory, but require a great deal of precision both in the manufacture of the individual parts and in their assembly. It would be an advantage to have an arrangement which could be completely assembled as a separate unit, then installed in the apparatus, and which would be self-locating in relation to the complementary device. Where devices are handled frequently, and occasionally mishandled, such as portable radios in public safety work, it is highly desirable to provide charging contacts which slide on the mating contacts, thereby providing self-cleaning capability. It is also desirable to accommodate devices of different dimensions.